Low-voltage string-lighting systems have been used extensively for decorating both private homes and commercial establishments. String-lighting systems are ideal for decoration because they can be displayed in various places and in nearly every imaginable form. For example, low-voltage string-lighting systems are often used to decorate walls, floors, ceilings, and staircases, of restaurants, nightclubs, hotels, and movie theaters. One of the more common commercial uses of string-lighting systems is aisle lighting in movie theatres, where a string of lights is placed down each side of an aisle.
A typical low-voltage string-lighting system, such as those used for aisle lighting, includes a power line having multiple light fixtures attached thereto (hereinafter a "light string"), an external housing made of a durable material such as vinyl or aluminum, and an external covering which is translucent and generally fits within the housing. The external housing is typically manufactured by an extrusion process and is commonly referred to in the lighting industry as an extrusion. Accordingly, that external housing shall be referred to as a housing extrusion.
A single light string in a common string-lighting system may include dozens of individual light bulbs. Because string-lighting systems include so many light bulbs, it is common for some of the bulbs to burn out. Thus, it is frequently necessary to replace one or more light bulbs on a light string. It may also be desirable to change light bulbs for decorative reasons, for example, to change the bulbs to a different color. It is therefore desirable to have a decorative string-lighting system which has easily replaceable light bulbs.
Conventional string-lighting systems have fallen short of this goal. In order to replace a single light bulb in some conventional string-lighting systems, it is necessary to twist or solder the light bulb leads onto a spliced section of the power line. Thus, the process of connecting individual light bulbs is very time consuming and inconvenient. Because of the complexity of the connection described above, it is possible that a poor connection may be made that could result in an electrical short circuit.
One prior art lighting system which attempted to facilitate bulb replacement is shown in U.S. Pat. No. 4,514,791. In this system, the bulb has a pair of leads bent over a circular casing which is then inserted into a socket. The electrical contact between the conducting wires and socket terminals requires soldering to affix the socket to the wires.
A system of this kind includes many drawbacks. In particular, because it may be necessary to replace a light bulb several times for a specific socket, the terminals within the socket are likely to become deformed so that a loose connection occurs between the light-bulb leads and the terminals. A system of this sort also includes the additional disadvantage requiring a custom set of conducting wires which are exposed at predetermined locations. Finally, the connection between the socket and the wire is poor because it is often desireable to bend or shape a light string. Thus, it is possible that the solder connections will be placed under considerable stress so that the durability of the soldered connections is compromised.
In another string-lighting system, the leads of each light bulb are inserted directly into holes provided within each socket. See for example U.S. Pat. No. 4,482,944. The conducting terminals within each socket are formed so that they act like spring clips. The leads are then inserted into the socket so that the conducting terminals exert pressure on either side of the inserted leads and hold the leads fast. Each conducting terminal is spot welded onto a conducting belt.
This system has the disadvantages of deforming the contact terminals and stressing the connections between the conducting terminals and the conducting belts. Furthermore, because the leads of ordinary low-voltage light bulbs are quite thin, a number of these leads will be bent or broken while inserting the bulbs into the socket.
In addition to the problems of replacing individual light bulbs in conventional string-lighting systems, further problems exist when replacing an entire string-lighting system. It is often desirable to replace a string-lighting system when the old assembly has deteriorated. In addition, it is sometimes desirable to replace a string-lighting system which does not have the latest features. However, replacing a conventional string-lighting system is very time consuming and costly. The housing extrusions of a typical string-lighting system usually are mounted to a surface (e.g., a floor) by an adhesive or rivets. Often it is necessary to tear out carpet, wallpaper, or other decorative items which surround the mounted housing extrusions when replacing a string-lighting system.
Because conventional replacement procedures for a string-lighting system are time consuming, an economic burden may be placed on a facility which is required to close down for the duration of the replacement process. In many cases, only the light string or the external covering of the string-lighting system is in a deteriorated condition, while the more durable mounted housing extrusion is still suitable for use. Thus, in many instances it is desirable to replace only the light string or the exterior covering of the string-lighting system. For these reasons, it would be preferable if the string-lighting system that was already installed could be altered to look like new in a short period without having to tear out the mounted housing extrusions that are already in place.
In conventional string-lighting systems, the housing extrusion is provided with a rectangular groove which houses the light string. Typically, a removable external covering is then situated within the rectangular groove so that the light string is encapsulated by both the external covering and the housing extrusion. Some manufacturers produce housing extrusions which have different dimensions than housing extrusions produced by other manufacturers. For this reason, it is difficult to provide an external covering which is retrofitting and which can be fitted to housing extrusions of different manufacturers. Thus, if the owner of a string-lighting system wants to replace his system without replacing the housing extrusions, the owner would be forced to return to the same manufacturer for an external covering even if he were not completely satisfied with that manufacturer's external covering. This problem is further aggravated if the manufacturer of a particular string-lighting system has gone out of business, or has stopped producing a particular model, so that the owner is forced to tear out the mounted housing extrusions in order to obtain a new string-lighting system. A need exists for a string-lighting system which is easily replaceable and which provides a retrofitting external covering that can be used to refurbish the string-lighting systems of different manufacturers.
An object of the present invention is to provide a string-lighting system which has bulbs that can be replaced quickly and easily. Another object of the present invention is to provide a string-lighting system which is durable despite repeated replacement of light bulbs. Another object is to provide a light fixture which is securely fastened to the conducting wires without the need for soldering or the like. Moreover, the socket is releasable but tightly secured within the fixture.
A further object of the present invention is to provide a retrofitting cover for preexisting housings of different manufacturers. The cover would allow the refurbishing of the old systems with the present invention without the costly removals of housings, which are affixed to the lighted structure. The retrofitting cover is aesthetically pleasing, therefore allowing the system to appear new and attractive.